Oral FMT (Fecal Microbial Transplant) in Subjects With Multiple Sclerosis

The specific aims are to: 1. Determine the tolerability of a single dose of 30 capsules in a group of adults with MS 2. Determine whether any unexpected outcomes arise in participants who successfully complete an FMT procedure consisting of a single dose of 30 capsules 3. Determine whether successfully completed FMT leads to engraftment of donor microbiome in participants 4. If the FMT leads to engraftment of donor microbiome in participants, determine whether participants revert back to previous microbiome profiles, and if so, at what time point 5. Determine whether engrafted species following the FMT, if detected, result in any changes in immune or metabolomic parameters relative to baseline 6. Determine whether the FMT has any adverse impact, relative to baseline, on study participants' self-reported levels of fatigue, mental well-being, and health-related qualify of life 7. Determine whether the FMT has any adverse impact, relative to baseline, on study participants' neurological status, relative to baseline The study population will consist of adults with clinically definite MS who are currently untreated with any disease-modifying therapy or are being treated with glatiramer acetate or interferon beta. The research team will offer study participants a single FMT procedure in the form of 30 oral capsules which contain fecal material. Study participants will visit Griffin Hospital facilities 8 times. The first visit will involve a clinical screening. Of the 7 remaining visits, 6 will involve data collection and one will involve the FMT procedure.